docs: def _get_magnitude_vector_properties(catalogue, config):
      '''If an input minimum magnitude is given then consider catalogue
      only above the minimum magnitude - returns corresponding properties'''
  
      mmin = config.get('input_mmin', np.min(catalogue['magnitude']))
      neq = np.float(np.sum(catalogue['magnitude'] >= mmin - 1.E-7))
      return neq, mmin